Apparently, the Americans discovered a report at the DFS and had it translated. Actual drawings of the aircraft in question appear near the end of the PDF document linked from this site. What is extraordinary is that it mentions a diffusor and a power output of 60,000 horsepower. (NACA TM 1106)
http://naca.central.cranfield.ac.uk/report.php?NID=2957
Enjoy,
Ed